391471609 has 8 divisors (see below), whose sum is σ = 407930760. Its totient is φ = 375209856.

The previous prime is 391471589. The next prime is 391471637. The reversal of 391471609 is 906174193.

It can be written as a sum of positive squares in 4 ways, for example, as 116575209 + 274896400 = 10797^2 + 16580^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 391471609 - 2¹³ = 391463417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (391477609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45294 + ... + 53239.

It is an arithmetic number, because the mean of its divisors is an integer number (50991345).

Almost surely, 2^391471609 is an apocalyptic number.

It is an amenable number.

391471609 is a deficient number, since it is larger than the sum of its proper divisors (16459151).

391471609 is a wasteful number, since it uses less digits than its factorization.

391471609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98699.

The product of its (nonzero) digits is 40824, while the sum is 40.

The square root of 391471609 is about 19785.6414856835. The cubic root of 391471609 is about 731.5321600965.

The spelling of 391471609 in words is "three hundred ninety-one million, four hundred seventy-one thousand, six hundred nine".